Over the last decade or so, for most businesses, it has become a necessity for employees to share data over local area networks. To improve efficiency, enhancements have added to a local area network such as remote wireless access. This enhancement provides an important extension in forming a wireless local area network (WLAN).
Typically, a WLAN features a wireless network interface card and a wireless access point (AP). The network interface card enables one or more wireless devices, such as a laptop computer or personal digital assistant, to communicate with the AP over the air. The AP operates as a relay station by receiving data frames from the network interface card and transmitting data from these frames to a fixed, backbone network. Thus, the AP supports communications with both a wireless network and a wired network.
Over the past few years, a number of WLAN standards have been developed. For instance, the 802.11 standard was originally developed for 1 Mbps and 2 Mbps data rates approximately in a 2.4 gigahertz (GHz) band. Other standards include “Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: Higher-Speed Physical Layer Extension in the 2.4 GHz Band” (IEEE 802.11b, 1999) and “Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: High-Speed Physical Layer in the 5 GHz Band” (IEEE 802.11a, 1999). IEEE 802.11b is a standard for a data rate up to 11 Mbps generally in the 2.4 GHz band. IEEE 802.11a is a standard for a data rate up to 54 Mbps generally in the 2.4 GHz band.
Additional 802.11 standards are being developed for supporting additional functionality. For instance, the standard which is expected to be the most widely deployed in the near future is the revised IEEE 802.11 standard “Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications” (IEEE 802.11, 1999). IEEE 802.11 actually encompasses a number of WLAN standards that have already been formalized.
One problem associated with conventional APs is that such equipment is designed to support specific, existing wireless network standards. If a new WLAN standard is developed and support for this standard is desired, a new set of APs supporting the new WLAN standard must be deployed. This can be accomplished by deploying new APs operating in parallel with old APs or replacing the old APs with newer APs supporting both old and new WLAN standards. In either case, support for any new WLAN standard requires deployment of a whole new array of APs, which is quite costly.